Method for extracting compositions from plants

Abstract

Methods for extracting and concentrating cannabinoids using ultrasound-enhanced solvent extraction. Freshly harvested cannabis plant materials, which may be selectively chosen plant parts or the entire plant itself, are shredded to a particular particle size. The plant material is then mixed with a solvent to form a slurry, and thereafter subjected to ultrasound to release intracellular contents into the solvent. Filtering steps are then applied to remove biomass, waxes and chlorophyll. Water removal and solvent recovery steps are further applied to ultimately derive an extract having high concentrations of target cannabinoids, and in particular cannabidiol (CBD). The methods may be deployed on-site in batch or continuous flow processes, and may further be utilized to derive other types of materials from plants, such as essential oils.

What is claimed is: 
     
       1. A method for extracting and concentrating CBD from hemp plant material comprising the steps:
 a) harvesting a hemp plant from which said hemp plant material is derived; 
 b) shredding or grinding said harvested plant in step a) to produce particulate hemp plant material; 
 c) mixing said particulate hemp plant material in step b) with an ethanol solvent to form a slurry; 
 d) subjecting said slurry produced in step c) to ultrasonic energy, said ultrasonic energy being applied at a frequency ranging from 5 kHz-1 MHz and having a displacement amplitude in the range from about 20 to 100 mm with power being delivered to said slurry in a range from about 90 to about 160 watts per square centimeter of slurry treated, said ultrasound being applied for a duration ranging from 30 seconds to 5 minutes; 
 e) filtering said slurry treated with ultrasound in step d) to remove wax, biomass and chlorophyll to derive a liquid extract; and 
 f) treating said extract produced in step e) to remove water emanating from said hemp plant shredded in step b) and residual ethanol solvent introduced in step c) to produce a concentrated resultant extract. 
 
     
     
       2. The method of  claim 1  wherein in step b), said hemp plant material is shredded or grinded to have a particle size ranging from 1 to 12 mm. 
     
     
       3. The method of  claim 2  wherein said particle size ranges from 2 to 6 mm. 
     
     
       4. The method of  claim 1  wherein in step b) said particulate hemp plant material is shredded or grinded to have a particle size operative to pass through a 0.5 inch mesh screen. 
     
     
       5. The method of  claim 4  wherein said particulate hemp plant material is operative to pass through a 0.25 inch mesh screen. 
     
     
       6. The method of  claim 1  wherein in step c), the amount of ethanol solvent added to particulate hemp plant material will range from 25 mL of ethanol solvent per 50 grams of particulate hemp plant material to 25 mL of ethanol solvent per 0.1 gram of particulate hemp plant material. 
     
     
       7. The method of  claim 6  wherein in step c), the ratio of ethanol solvent to hemp plant material ranges from 25 mL of ethanol solvent per 10 grams of particulate hemp plant material to 25 mL of ethanol solvent per 2 grams of particulate hemp plant material. 
     
     
       8. The method of  claim 7  wherein step c), the range of ethanol solvent to particulate hemp plant material will range from 25 mL of ethanol solvent per 10 grams of particulate hemp plant material to 25 mL of ethanol solvent per 5 grams of particulate hemp plant material. 
     
     
       9. The method of  claim 1  wherein said ethanol solvent is maintained at a temperature of around −40 to −60° C. when mixed with said particulate hemp plant material to form said slurry. 
     
     
       10. The method of  claim 1  wherein in step d), said ultrasound is applied at a frequency ranging from 10 kHz to 60 kHz. 
     
     
       11. The method of  claim 10  wherein said ultrasound is applied at a frequency of 40 kHz. 
     
     
       12. The method of  claim 1  wherein said ultrasound possesses a displacement amplitude of 80 mm. 
     
     
       13. The method of  claim 1  wherein in step d), said ultrasound is applied for a duration ranging from 30 seconds to 120 seconds. 
     
     
       14. The method of  claim 1  wherein step e) further comprises at least partially removing and further subjecting said biomass to ultrasound for a time, duration, frequency, and power sufficient to reduce the mass of said biomass. 
     
     
       15. The method of  claim 1  wherein step e) further comprises recovering and recycling ethanol solvent from said post-ultrasound treated slurry. 
     
     
       16. The method of  claim 14  wherein step e) further comprises applying ultrasonic radiation at a frequency ranging from 35 to 130 kHz for a duration ranging from 5 to 20 minutes and at an intensity of 50-60 watts per square centimeter. 
     
     
       17. A method for extracting and concentrating CBD from hemp plant material comprising the steps:
 a) harvesting a hemp plant from which said hemp plant material is derived; 
 b) shredding or grinding said harvested plant in step a) to produce particulate plant material; 
 c) mixing said particulate plant material in step b) with an ethanol solvent to form a slurry; 
 d) subjecting said slurry produced in step c) to ultrasonic energy, said ultrasonic energy being applied at a frequency ranging from 5 kHz-1 MHz and having a displacement amplitude in the range from about 20 to 100 mm with power being delivered to said slurry in a range from about 90 to about 160 watts per square centimeter of slurry treated, said ultrasound being applied for a duration ranging from 30 seconds to 5 minutes; and 
 e) sequentially filtering said slurry produced in step d) to remove biomass, chlorophyll and wax to derive a liquid extract; and 
 f) heating said extract produced in step e) to vaporize and separate water emanating from said hemp plant shredded in step b), and ethanol solvent introduced in step c) to isolate a concentrated resultant extract. 
 
     
     
       18. The method of  claim 17  wherein in step b) said plant material is shredded or grinded to have a particle size operative to pass through a 0.5 inch mesh screen. 
     
     
       19. The method of  claim 17  wherein in step c) said ethanol solvent has a temperature of −40° C. or less. 
     
     
       20. The method of  claim 17  wherein step f) further comprises reducing the pressure while concurrently heating said extract. 
     
     
       21. The method of  claim 20  wherein step f) comprises wiped-film evaporative oil-solvent separation. 
     
     
       22. The method of  claim 21  wherein in step e), said chlorophyll is removed by the sequential application of membrane filtration and activated carbon.